1. Field of the Invention
The invention relates to a testing apparatus, and more particularly to a circuit testing apparatus for testing the capacitance of a capacitor of a device under test.
2. Description of the Related Art
Along with the advancements in integrated circuit (IC) technology, both the functionalities and importance of ICs have increased. Besides basic analog ICs and digital ICs, several kinds of ICs which are capable of processing both analog and digital signals are presented from markets. Such kinds of ICs are generally called mixed signal ICs. Regardless of any type of IC, such as the basic analog ICs, the basic digital ICs, or the mixed signal ICs, each IC will be tested after being manufactured to ensure quality. Additionally, according to the test result, each IC will be determined to have passed or failed the test, and only the ICs that pass the test will be provided to downstream customers.
FIG. 1 illustrates a dedicated testing apparatus for testing capacitance of a capacitor of a device under test. A variety of dedicated testing apparatuses may be used to test the functionalities of the device under test (e.g. an IC). As shown in FIG. 1, if the device under test 12 has a capacitor C, measuring the capacitance of the capacitor C needs the dedicated testing apparatus 10. The dedicated testing apparatus 10 transmits an initial testing signal ST to the device under test 12 for measurement of the capacitance, and then tests two terminals of the capacitor C to acquire the signal in response to the testing signal ST. Accordingly, the capacitance of the capacitor C may be obtained by determining the received signals from the capacitor C.
However, the price of a dedicated testing apparatus 10 is very expensive. Furthermore, besides the dedicated testing apparatus, there are no other generic testing apparatuses with capability of testing capacitance, which is inconvenient to users. Thus, it is required improving a generic digital logical testing apparatus to test the capacitance of a capacitor within a device under test.